Fluid engine



@enigmes-same 6 2 Patented Mar.2o,1945

UNITED STATES Search Room PATENT OFFICE 6 Claims.

My invention resides in novel features of construction and in the arrangement and combinak tion of certain of its component parts. The foregoing and other objects and advantages will appear in the following description and from the drawing showing one embodiment, and my invention will hereafter be more fully defined in the appended claims.

Fig. 1 is a vertical section of a hydraulic trans mission embodying my invention.

Fig. 2 is a view of the transmission bracket, the left half being viewed from the outside and the right half from the inside.

Fig. 3 is an enlarged sectional view of the piston showing its relation to associated parts.

Fig. 4 is a cross sectional view taken through the control partition and showing particularly the uid transfer ducts, replenishing ducts and check valves.

Fig. 5 is a plan view, partly in section, of another embodiment of my invention suitable for use as a iiuid engine such as a pump, motor, etc.

In Figures l to 4 inclusive, I have shown a preferred form of hydraulic transmission embodying my invention. It comprises a pump unit P and motor unit M enclosed by a stationary housing, preferably made up of a central section II which with bracket I2 forms a pump compartment and with bracket I2 forms a moto-r compartment. The same numerals are used to designate identical parts in the pump and motor units and the prime mark is applied merely to indicate that such part is also found in the motor unit where, in mcst instances it is shown in a different position and is more readily identied. The pump compartment is separated from the motor compartrnent by a substantial partition I3 which may form an integral portion of the housing section II, The partition is provided with laterally arranged, and in the present embodiment, convexly conical valve faces I 4, I4' and with fluid transfer ductg I5 and I6 between valve faces, extending circumferentally substantially as shown and serving jp conduct fluid between the units. Each compartment contains a rotatable cylinder element comprising a power shaft portion Il, a cylinder portion I8, and a central or spherical journal portion I9, all operating as a unit and preferably formed in one piece. The cylinder portion is provided with a concavely conical face arranged in close proximity to the valve face to form a working clearance therebetween, and is further provided with a plurality of open ended laterally arranged and preferably inclined cylinders 20 exit should be understood that the valve and cylinder faces may be nat instead of conical, when a substantially complete displacement by the pistons is not essential, or when other factors make this desirable. The arrangement of the cylinders in an inclined position to extend outwardly from the valve face in combination with other features of construction and arrangement is not claimed herein but forms subject matter of my copending application Serial No. 504,030, filed September 27, 1943. I provide means for transferring the thrust from the cylinder element to the central section of the housing, or directly to the valve partition as shown. This is preferably accomplished by providing a raceway 2l directly in the outer periphery of the cylinder portion, securing a bearing race element 22 to the housing or partition by the locknut 23 and interposing spherical bodies 24 therebetween. The other end of the cylinder element is operatively supported in the housing by the ball bearing 25 associated with the power shaft and bracket I2. In instances when a moderate uid pressure is used involving no considerable distortion of the housing or other parts, the ball bearing 25 may be permitted to carry the thrust from the cylinder element, in which case the thrust bearing elements 22 and 24 may be omitted and the cylinder portion I8 may be centered and supported by the pilot bearing 12, The central portion I9 of the cylinder element is shaped to form a spherical journal and is provided with a pair of oppositely positioned laterally extending arcuate driving raceways 26, 21 arranged concentric, and having driving surfaces aligned with the center of the spherical journal. The cylinder element thus formed has great strength and rigidity and its working face has a relatively small diameter well suited for rapid rotation with respect to valve face. Its thrust area is relatively near its rotational center and does not tend to spring the cylinder element to any extent, and its thrust bearing even though of relatively moderate diameter has a large thrust capacity which, together with its arrangement near the valve face, makes it possible to secure and maintain a small working clearance substantially unaifected by distortion or elongation of the housing or other parts, and results in a substantial reduction of valve leakage, even with ex tremely high fluid pressures.

Each unit is provided with a rotatable annular element 28, which will hereafter be referred to as the piston element, each provided with a spherical bearing surface operatively associated with tending outwardly from the valve face; although u spherical journal I9 and with a plurality of concavities 29 on one side of its outerly portion shaped ,to form spherical bearing surfaces. I provide effective means for transferring a substantial portion of the iiuid pressure thrust from within the cylinder directly to the piston element. This means comprises a piston body 30 having a cylindrical portion tted within the cylinder and an inner flange provided with an inwardly facing concave bearing surface and an outwardly facing convex bearing surface, and a piston rod 3| provided at one end with an expanded portion 32 shaped to form a convex bearing surface in operative contact with the inwardly facing bearing surface and with a collar or shoulder 33 shaped to form a concave surface in operative contact with the outwardly facing bearing surface of the piston ange. The other end of the piston rod is also provided with an expanded spherical portion 34 having an outerly convex portion in operative contact with the bearing surface in cavity 29 and a substantial inner portion out of contact with the cavity surface so as to form a pressure chamber 35 therebetween. A locknut 36 retains the spherical journal 34 in the cavity and a duct 31, extending lengthwise through the piston rod, connects the pressure chamber 35 with the interior of the cylinder. It will be seen that the expanded portion 32 of the piston rod is di rectly exposed to fluid pressure in the interior of the cylinder and transmits a large portion of thrust directly to the piston rod and if its diameter is made nearly that of the cylinder, the exposed area of the piston 30 is small so that only a small portion of the total thrust need be transmitted through the spherical bearing surface of the shoulder 33. The diameter of the spherical journal 34 at the other end of the rod is preferably made to exceed the diameter of the cylinder. The exposed area in chamber 35 may then be made to equal that of the cylinder for a transfer of the entire thrust directly to the element 28, the spherical bearing surfaces in cavity 29 serving merely as a universal seal to limit fluid leakage. This construction of the piston and associated parts permits the use of extremely high iiuid pressures without excessively loading the pisto-n rod bearing surfaces.

Each of the annular piston elements 28, 28 is arranged to rotate synchronously with its cylinder element, but on an axis angularly displaced therefrom. This is accomplished by universal driving means rotationally connecting the cylinder elements with the piston elements; each driv- .ing means comprising a driving pin 38' extending through the hollow center of sphere I9' and radially through driving bores in the piston element 28', and a pair of taper rollers 39', 40 interposed between pin 38 and driving raceways 26', 21. The rollers are secured against outward movement by a sleeve 4 I and are preferably firmly locked together by some means such as the locknut 42' to form with the pin 38 a self centering unit which prevents the rollers from thrusting outwardly against the piston element 28 and serves to divide the torsional load evenly between driving raceways. The outer surface of sleeve 4I may form a raceway for an anti-friction bearing or may serve as a journal operatively fitted within the driving bores as shown in the drawing. It will be seen that the above described universal driving means is capable of transmitting a large torque and because of the laterally arranged raceways its operation is not affected by a slight lateral displacement between the cylinder and piston elements that may be caused by stretching or distortion of the housing or other parts.

I provide means whereby the rotational axis of piston element 28 may be shifted with great ease even under heavy load conditions. This is acccmplished by a thrust bearing having a nonrotating but tiltable thrust element 43 provided on one side with a raceway and spherical bodies 44 interposed between it and element 28', and having its other side preferably directly shaped to form integrally therewith a pair of convexly arcuate and open ended raceways 45 arranged, one on each side of shaft I1 and concentric with respect to the spherical journal I9 and with respect to a pair of concavely arcuate and also open ended raceways 46, formed preferably directly in the bracket I2, each concave raceway being aligned with a convex raceway to form a pair of operatively associated raceways engaging with a plurality of spherical rolling bodies 41. I further provide means for maintaining the rolling bodies in operative contact over substantially the entire concave raceway arc, regardless of the position of the piston element, and for this purpose provide a closed circuit for each pair of associated raceways. The closed circuit is preferably formed by a pair of lateral ducts 48 at the ends of each concave raceway, which extend through the bracket and are connected by an outer duct 49, formed partly by the bracket and partly by a retaining cover 50, the small covers 5I being provided to guide the spherical bodies from the duct 48 into the raceways. The above described arrangement distributes the thrust over a considerable circumferential portion of the housing, permits very large thrust loads without undue distortion and makes it possible to vary the rotational axis of the piston element with ease. The spherical bodies 41, particularly near the ends of the arcuate raceways, also serve as effective fulcrum elements for the circumferential transfer of torque between the rotating elements and the housing.

The speed of the motor shaft I1 may be varied and its direction of rotation may be reversed simply by tilting the pump piston element 28 from one side to the other side. However, I provide means for tilting both piston elements simultaneously in such a way as to secure a wide speed variation, and reversal of rotation between shafts with but a single control lever. It consists of a control element or jackshaft 52, supported Within the housing by ball bearings 53, 54 and provided at one end with a control lever 55 and at the other end with a pair of angularly displaced eccentrics such as the pivots 56, 5T to which the arms of the piston elements are connected by means of rods 58, 59. The pivots are arranged with respect to the control lever and each other as shown by the full lines. With the control lever in position F, pump element 28 is in its extreme left position and the pistons operate at maximum stroke but the motor element-28'Ais in an intermediate position, that is in a position in which the piston stroke is less "than their maximum. This adjustment causes the motor shaft to rotate in the same direction as, but faster than the pump shaft and corresponds to overdrive. When the control lever 55 is moved to the right, the pivots move toward the positions shown by the dotted lines reducing the pump stroke and at the same time increasing the motor stroke; the motor shaft slows down and comes to a stop when control lever -55 reaches the position N, in which position the rotational axis of element 28 coinif, metano al 'S cides with that of the cylinder element and the pump piston stroke is zero. However, the piston stroke of the motor is now at its maximum and therefore in a position of maximum torque, and as control lever 55 is moved toward R, the pressure in, and uid ow from the pump reverses and now drives the motor shaft in reverse direction. It will be seen that the motor is in position of substantially maximum stroke during a considerable range on both sides of neutral when a maximum torque multiplication is required, and moves into a position of reduced stroke and torque substantially only during high speed operation when a moderate torque is sufficient to drive the load.

In hydraulic devices having a closed fluid circuit it is important to replenish the circuit with liquid to compensate for leakage. I provide means for replenishing the circuit so as to permit a reversal of pressure in the device as well as a reversal of rotation. This is accomplished by connecting both trailing circumferential duct ends 60, `iii shown in Figure 4, with a pair ofA ball check valves 62, 63. and further by connecting the leading circumferential duct ends 64, 65, with another pair of ball check valves 66, 6l. Assuming rotation of cylinder element in the direction shown by the arrow and pressure in the duct p, the valves 63 and El are held closed by the pressure. The valve 66 is also held closed, especially during high rotative speeds of the cylinder element, when the separating walls between cylinders operate as vanes and liquid is impelled against the duct end 64, impact of the liquid tending to build up pressure. However, such rotation and action of the vanes impelling liquid towards 64, draws it away from and creates a partial vacuurn at the point of the duct end 60, causing the valve 62 to open and admit liquid through the passage 68, which may be connected with a source of liquid or with the reservoir formed by the lower portion of the housing. When pressure in tle device reverses but rotation remains in the same direction, liquid is admitted through valve 63, and when rotation reverses but not the pressure. the valve 65 opens, and when boti pressure and rotation are reversed. liquid is drawn in through the valve 61.

My device may be constructed as an individual engine unit for operation with a compressible or liquid uid and for use as a pump, a motor, or for other purposes requiring a xed or variable stroke positive displacement device; or two or more such units may be arranged at a distance from one another and connected together by pipes or the like for transmitting or controlling power between separated points. An individual unit is shown in Fig. 5. The construction of this unit is identical with that of the pump er motor heretofore described and differs therefrom merely in that the housing has been modified to form a single compartment and so as to form an inlet duct 69 and an outlet duct 10 for the passage of fluid into and out of the device;- the control rod 1l being arranged to extend from the casing for manipulation in any desired manner.

From the foregoing it will be seen that my construction and arrangement of the various parts permits the use of a very high uid pressure and enables me to secure great power from a device of moderate size. Furthermore it permits a reduction in the quantity of fluid which need be conducted between tre units and a corresponding reduction of the inertia losses secured thereby as well as by the arrangement of the cylinders in (ill Search Room an inclined position which, with other features of construction permits the fluid to flow into and out of the unit nearest the center of rotation where it is subjected to only a moderate centrifugal force. Furthermore the wide open cylinders and large section transfer ducts facilitate the smooth and unobstructed ow of uid between units, and taken with other factors above mentioned, permit efficient operation at high revolutions.

It should be noted that various changes may be made in the details of construction and combination of the various parts of my device and one or more of the features disclosed herein may be used in the illustrated or other embodiments without departing from the spirit of my invention, and I desire to cover by my claims such changes and other embodiments which may reasonably be included within the scope of my invention.

I claim as my invention:

l. In a fluid engine: the combination of a etationary housing having a bracket and a valve element shaped to form a valve face and provided with inlet and outlet ducts terminating in said valve face; a rotatable cylinder element having a central portion provided with a spherical journal and a pair of cppositely positioned laterally extending arcuate raceways arranged concentric with the spherical journal, a shaft portion extending toward the bracket from one side of the central portion and a cylinder portion extending from the other sid: of saidvcentral portion shaped to form an outer raceway and a cylinder face arranged adjacent the valve face to form a working clearance therebetween and provided with a plurality of cylinders extending from said cylinder face; means for limitng the working clearance between the valve and cylinder faces including an anti-friction cylinder thrust bearing having an element bearing against an outer portion of said valve element and rolling bodies bearing against said outer raceway; bearing means for supportng the shaft portion by said bracket; an annular piston element operatively associated with said spherical journal and adapted to rotate therewith but on an axis angularly displaced therefrom: driving means between the cylinder and piston elements, said driving means includ'ng a driving pin supported by and extending radially through the interior of the piston element and operatively associated therewith. and a pair of rolling bodies interposed between the pin and said arcuate raceways; pistons in the cyl'nders and means for operatively connecting the pistons with one side of the piston element; a movable anti-friction thrust bearing operatively associated with the other side of the piston element having a stationary element and rolling bodies; and means for angularly dsplacing the rotational axis of the piston element with respect to that of the cylinder element, said last mentioned means including a pair of convexly arcuate raceways xedly associated with said piston thrust bearing, a pair of concavely arcuate raceways fixedly associated with said end bracket and arranged so that each concave raceway and one of the convex raceways form a pair of operatively associated raceways. and rolling bodes interposed between each pair of operatively associated raceways.

2. In a fluid engine: the combination of a stationary housing provided with a valve face; a rotatable cylinder element having a shaft portion, a cylinder portion provided with a plurality of cylinders operatively associated with said valve face cylinders operatively associated wi cylinders and means for operatively connecting 10 the pistons with the piston element; means for operatively supporting both ends of the cylinder element by the housing; a thrust bearing for transferring the thrust from the piston element to the housing; and driving means between the cylinder and piston elements, said driving means including a pair of taper rollers associated with said driving raceways, a pin extending radially through the rollers and supported by said piston element, a sleeve associated with said pin, and

means including the sleeve and pin for securing the rollers against outward movement.

3. In a fluid engine: the combination of a stationary housing provided with a valve face; a

rotatable cylinder element having a shaft portion,

a cylinder portion provided with a nlllrality of saiiwilv? face, and a central portion provided with a spherical journal and a pair of oppositely positioned laterally extending arcuate driving raceways; an

annular piston element provided with a spherical bearing surface in operative association with the spherical journal and adapted to rotate with the cylinder element but on an axis angularly displaced therefrom; pistons in said cylinders and means for operatively connecting the pistons with the piston element; driving means between the cylinder and piston elements including a driving pin supported by and extending radially through the interior of the piston element and a pair of rolling bodies interposed between the pin and said driving raceways; an anti-friction thrust bearing for transferring thrust from the cylinder element to the housing; and an anti-friction thrust bearing for transferring the thrust from the piston element to the housing.

4. In a fluid engine: the combination of a stationary housing having an end bracket and a valve face; a rotatable cylinder element having a plurality of cylinders yoperatively associated with said valve face; means for operatively supporting the cylinder element by the housing; an annular piston element adapted to rotate with said cylinder element but on an axis angularly means for operatively connecting the pistons with the piston element; universal driving means for rotationally connecting the cylinder element with the piston element; and means for transferring 'displaced therefrom; pistons in said cylinders and l55 the thrust from the piston element to the housing and fIoLangnl l1.displaciingitlieA rotational. axis I n g l n l cliindenelegient, said means including a pair of convexly arcuate raceways xedly associated with said piston element, a pair of concavely arcuate open ended raceways xedly associated with said bracket, arranged so that each concave raceway and one of said convex raceways form a pair o! operatively associated raceways, rolling bodies interposed between each pair of operatively associated raceways, and means for connecting one open end of each concave raceway with the other open end to form a closed circuit for the passage of said rolling bodies.

5. In a fluid engine: the combination of a stationary housing having an end bracket and a valve face; a rotatable cylinder element having a plurality of cylinders operatively associated with said valve face; means for operatively supporting the cylinder element by the housing; an annular piston element adapted to rotate with said cylinder element but on an axis angularly displaced therefrom; pistons in said cylinders and means for operatively connecting the pistons with the piston element; universal driving means for rotationally connecting the cylinder element with the piston element; a thrust bearing associated with said piston element having a thrust element adapted to be shifted; and means for angularly displacing the rotational axis of the piston element with respect to that of the cylinder element, said means including a pair of convexly arcuate raceways xedly associated with said thrust element, a pair of concavely arcuate raceways xedly associated with said bracket arranged so that each concave raceway and one of said convex raceways form a pair of operatively associated raceways, and rolling bodies interposed between each pair of operatively associated raceways.

6. In a fluid engine having a, cylinder element provided with a cylinder adapted to be subjected to fluid pressure and a movable element adapted to reciprocably extend into said cylinder: the combination with said cylinder and movable element of articulatable means for transferring a minor portion of said fluid pressure indirectly and for transferring a major portion of said uid pressure directly to said movable element, said means comprising an annular piston sleeve within said cylinder having a relatively thin outer rim exposed to fluid pressure in the cylinder adapted to receive said minor portion of uid pressure and having an inwardly extending flange formed integral With said sleeve provided with a concavely spherical bearing surface on one of its sides extending inwardly from said outer rim and with a convexly spherical bearing surface on its other side arranged concentric with each other; a shoulder associated with said movable element provided with a bearing surface in operative contact with said convexly spherical bearing surface for the transfer of the minor portion of uid pressure from the piston sleeve to said movable element; and a head associated with said movable element extending inwardly from said outer rim having one of its sides provided with a convexly spherical bearing surface in operative association with the concavely spherical bearing surface of said piston ange and having its other side exposed to fluid pressure within said cylinder for the transfer of the major portion of fluid pressure directly to said movable element.

ALFONS H. NEULAND. 

